Hello. My job is to help teens in this situation. I also have my own Sixth Former who is pondering his options!
With my professional head on, I’d say go and visit Unis on some open days. Find the courses he is interested in on UCAS. You can just pick a couple and get an idea. Often going to the Uni either completely rules or out, or they decide they really want to do this - it can be fear of the unknown! At least give it a go. Also, if you have a Uni near you that does the courses he’s interested in, he can still live at home.
It’s a shame he doesn’t have careers guidance, but is there a Head of 6th or similar who will go through your son’s options with him? You say he wishes to earn well - Uni grads usually get paid higher than those who don’t attend Uni (can’t recall the stat).
However, I’ve had a student in last year’s cohort who is doing an AMAZING degree apprenticeship! It’s outing if I give details, but he’s guaranteed a job at the end of it, is already earning, and is currently working on his degree! This is a fantastic option for those who don’t wish to stay purely in academia (and who want to be earning!)
When looking at regular apprenticeships, do check they are level 4 as A levels are level 3 and he’s already studying at level 3. (No point repeating level 3). Tell him not to worry too much about Mocks, BUT he must put in the work now. My advice is whatever you find yourself doing at the moment, do it to the best of your ability. So many students regret not making the most of 6th form, and other students thrive from the effort they put in.
Sorry this is long, but I feel passionately about young people understanding the opportunities open to them! (I guess that’s why I’m doing the job I do)!!
As a parent - good luck! I know exactly how teenage boys are!! Work with him though, as you seem to be doing already, and it’ll come good 😊👌